Round-Trip Time

Deep dive into network latency on the web: an interactive report based on Round-Trip Time (RTT) data from Chrome UX Report (CrUX).

Overview

This is an interactive report to explore network latency on the web. It addresses questions such as: What is the current health of the network? How does it vary by country and website categories? It uses Round-Trip Time (RTT) data from Chrome UX Report (CrUX).

RTT shows the time it takes for a request to go from a client to the server and back (round-trip). In CrUX, it is estimated on the initial page load navigation using navigator.connection.rtt and measured in milliseconds. CrUX provides 75th percentile (p75) aggregated for all domain visits during the past 28 days.

RTT is a diagnostic metric that helps you to understand your audience network connection. Instead of relying on 2G, 3G, or 4G labels (which are also based on RTT), it provides better visibility to your visitors' connection. For example, if your site's average RTT is slow, performance metrics like TTFB or LCP are also likely to be impacted. Consider loading some parts of your site conditionally (learn more). But if RTT is fast and you still have slow metrics, you need to optimize your site. We tried to define fast & slow buckets on the map below. To measure your site's performance, use our free Site Speed Test.

Methodology: we took RTT data for the top 50,000 domains aggregated during November 24 (excluding empty values, which resulted in 49,801). Here are the median (p50) values by device type:

Mobile
151ms
Desktop
96ms
All Devices
138ms

Usually, 70% of a website's traffic is mobile, which explains why the All Devices value is closer to Mobile than Desktop. The table below provides a detailed breakdown of the RTT distribution with percentiles and statistics:

Mobile
100ms
116ms
151ms
207ms
267ms
34ms
170ms
1773ms
48,876
All Devices
87ms
106ms
138ms
193ms
259ms
21ms
158ms
1766ms
49,801
Desktop
65ms
75ms
96ms
126ms
171ms
12ms
109ms
934ms
41,082

Geography

Let's explore RTT by country. The regional difference is clear and reflects countries' GDP and the location of data centers. Australia and New Zealand famously experience higher RTT due to speed of light limitations, as data centers are primarily located in the US and Europe. We computed regional RTT using top-level domains (TLDs). For example, .nl represents the Netherlands, and .ca is Canada.

The map below displays the median RTT (p50). And the table on the right lists the top 10 fastest and slowest countries. You can interact with the map and use the device switch to change aggregation.

<100ms
100–150ms
150–200ms
200–250ms
>250ms
Rank
Country
p50
1.
Netherlands
67ms
2.
Norway
79ms
3.
Sweden
82ms
4.
Denmark
84ms
5.
Belgium
89ms
6.
Germany
90ms
7.
Czechia
90ms
8.
Switzerland
90ms
9.
United Kingdom
92ms
10.
Hungary
92ms
...
...
...
61.
Uzbekistan
214ms
62.
Kazakhstan
216ms
63.
Egypt
221ms
64.
Venezuela
240ms
65.
South Africa
246ms
66.
Kenya
262ms
67.
Sri Lanka
273ms
68.
Iran
284ms
69.
Pakistan
294ms
70.
Nigeria
338ms

Categories

The network latency varies up to 50% by website category. Sectors like E-commerce or Auto-industry tend to invest more in web performance, resulting in lower RTT. In contrast, categories like Entertainment or Adult content, are much slower. To classify websites, we used Chrome's topic classifier (chrome://topics-internals/). Below is an interactive table to explore the network latency across different clusters of the web:

Adult Content
109ms
133ms
181ms
248ms
301ms
57ms
197ms
1002ms
6,442
Arts & Entertainment
107ms
125ms
168ms
226ms
279ms
57ms
183ms
751ms
10,013
Online Communities
104ms
122ms
167ms
226ms
276ms
52ms
181ms
713ms
2,755
All ☼
100ms
116ms
151ms
207ms
267ms
34ms
170ms
1773ms
48,876
Internet & Telecom
107ms
125ms
166ms
216ms
267ms
59ms
180ms
1773ms
3,147
Books & Literature
102ms
118ms
157ms
211ms
262ms
51ms
171ms
555ms
1,408
Jobs & Education
103ms
123ms
163ms
213ms
262ms
53ms
174ms
597ms
3,987
Computers & Electronics
108ms
127ms
163ms
212ms
258ms
55ms
176ms
1356ms
2,903
Games
106ms
122ms
155ms
200ms
258ms
57ms
169ms
699ms
2,935
Finance
105ms
118ms
150ms
194ms
255ms
62ms
165ms
557ms
2,357
Sports
97ms
115ms
137ms
186ms
250ms
57ms
157ms
614ms
2,248
Business & Industrial
98ms
116ms
143ms
190ms
249ms
59ms
162ms
1111ms
2,775
News
95ms
115ms
139ms
188ms
249ms
57ms
158ms
796ms
7,468
Law & Government
104ms
121ms
156ms
204ms
247ms
62ms
168ms
574ms
2,076
Travel & Transportation
99ms
116ms
137ms
173ms
222ms
62ms
152ms
820ms
1,352
Food & Drink
89ms
107ms
121ms
155ms
220ms
59ms
139ms
437ms
1,069
Autos & Vehicles
98ms
115ms
132ms
166ms
208ms
60ms
145ms
519ms
1,187
Shopping
89ms
105ms
122ms
155ms
203ms
52ms
137ms
726ms
4,928
Beauty & Fitness
89ms
104ms
119ms
150ms
195ms
54ms
134ms
396ms
1,130

Next: This is the first iteration of the report. We plan to expand its functionality once more RTT data is available in CrUX. Feel free to contact us via Email or Twitter and suggest your ideas and improvements.